JPH06106281A - Method for controlling outer diameter of coil spring - Google Patents

Abstract

PURPOSE:To keep the outer diameter of a coil spring within a specified allow ance with a high precision. CONSTITUTION:In a method for controlling the outer diameter of a coil spring, the sampling is executed at the rate of one for an appropriate number in the manufacturing process of the coil spring, the coil spring is held by a member of a parallel chuck before the sampled coil spring is cut, the outer diameter is measured, the measured value is received by a computer and compared with the reference value, and the position of the coiling pin is adjusted by the value corresponding to the difference.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION In order to keep the outer diameter of a coil spring within a predetermined permissible range, the present invention measures the outer diameter of the coil spring at a ratio of one to an appropriate number in the manufacturing process.
The present invention relates to a coil spring outer diameter control method for correcting a ring.

[0002]

2. Description of the Related Art It is essential that a coil spring has a constant free length and has a predetermined performance. Therefore, various improvements have been made. In recent years, however, the outer diameter of the coil spring has a predetermined allowable range. I was required to enter.
That is, if the outer diameter of the coil spring changes, the performance of the coil spring will be affected and it will not be possible to insert the coil spring into a predetermined dimension.

The outer diameter of the coil spring is affected by the wear of the tool. That is, FIG. 8 schematically shows a coil spring manufacturing apparatus. As shown in the drawing, a coiling pin 1 and a pitch tool 2 are provided, and a wire rod W, which is a raw material of the coil spring, passes through a wire guide 3. , A pair of feed rollers 4,
It is sent while being sandwiched between 5 and passes through the next wire guides 6 and 6a to come into contact with the coiling pin 1 to form a curved shape, which moves along the cored bar 7 and is moved by the pitch tool 2 to a predetermined position. It is spirally wound at a pitch, and when it reaches a predetermined length, it is cut by a cutting tool 8 to form a coil spring.

As shown in FIG. 5, the outer diameter of the coil spring is greatly affected by the wear of the coiling pin 1 portion 1a with which the wire W abuts and the outlet portion 6b of the wire guide 6a, particularly the wear of the coiling pin 1 portion 1a. Receive. In order to deal with this change in outer diameter, a method disclosed in Japanese Patent Laid-Open No. 3-35831 has been conventionally known as an outer diameter control method for a coil spring.

According to the method disclosed in the above publication, a close contact spring having a desired free length of the coil spring is manufactured, and then the outer diameter of the spring is calculated by a computer from the diameter of the wire rod required for the close contact spring and its developed length. Then, the position of the coiling pin 1 was adjusted based on the calculated value. Although the outer diameter was measured manually, there were problems as described below.

[0006]

As described above, in the method of forming the contact spring and calculating from the developed length of the wire rod, it is assumed that all the windings adjacent to each other are in contact, and it is not a direct measurement. The contact spring made for use is not used and is wasted. The manual measurement method requires manual labor, is prone to errors, and has a problem in accuracy.

An object of the present invention is to eliminate the above-mentioned problems of the prior art. Therefore, the outer diameter of the coil spring can be measured automatically, quickly and sufficiently accurately, and the measured value can be used for subsequent measurement. To provide an outer diameter control method for a coil spring, which can appropriately correct the outer diameter of the coil spring.

[0008]

The outer diameter control method for a coil spring according to the present invention is characterized in that the coil spring is sampled at an appropriate ratio of one in the manufacturing process, and the sampled coil spring has a predetermined length. Before reaching the point where the coil spring is cut, the outer diameter of the coil spring is measured by sandwiching the coil spring with a pair of members of a parallel chuck and measuring the distance between the members, and the measured value is stored in a computer. The input is compared with a predetermined reference value, and the position of the coiling pin is adjusted by a value corresponding to the difference between the measured value and the reference value.

[0009]

The coil spring sampled in the manufacturing process is clamped by the members of the parallel chuck so that the outer diameter is measured as the distance between the members. Therefore, the coil spring is accurately measured, for example, as in the caliper measurement. Since the position of the coiling pin 1 is corrected by comparing the value with the reference value, the outer diameter is appropriately corrected. Moreover, since it is not necessary to make a contact spring, it is possible to control the material quickly without wasting the material.

[0010]

Embodiments of the present invention will now be described with reference to the drawings. 1 to 4 show an example of an apparatus used for carrying out the outer diameter control method according to the present invention,
Similar to the apparatus shown in FIG. 8, a coiling pin 1 for forming the wire W to be sent in a curved shape and determining the outer diameter of the coil spring, and a pitch tool 2 for determining the pitch of the coil spring.
And wire guides 3, 6, 6a, wire rod feed rollers 4, 5,
A core metal 7 and a cutting tool 8 are provided.

Further, as a motion controller including a CPU (microcomputer) for controlling a pitch chuck 2 and feed rollers 4 and 5, a parallel chuck 9 and a coiling pin 1 described below. And a detector 11 for detecting the free length of the coil spring C in the manufacturing process. Further, as shown in FIG. 1, in connection with the pitch tool 2, a cam 12 for operating the pitch tool, a servo motor 13, and a drive unit 14 are provided.
And a rotary encoder 15 and a drive servomotor 16, a drive unit 17 and a rotary encoder 18 are installed in association with the pair of feed rollers 4, 5. Reference numeral 19 is a cylinder for driving the cutting tool 8, and 20 is a selector for the molded coil spring.

According to the present invention, in the manufacturing process of the coil spring, sampling is performed at an appropriate ratio of one, and the position of the coiling pin 1 is adjusted by the measured value of the outer diameter. Therefore, as shown in FIGS. 2 to 4, a parallel chuck 9 is provided close to the detector 11 on the side where the coil spring C is unwound, and the parallel chuck 9 preferably has a pair of air pressures that are close to and away from each other. Material (claw) 9
a and 9b, the coil spring is sandwiched by these members, and the outer diameter of the coil spring is measured as the distance between the members. Therefore, the parallel chuck 9 can use an appropriate measuring device for measuring the distance between the members, for example, a contact type displacement sensor, an eddy current displacement sensor, or the like, but preferably a laser measuring device is provided. .

Since the position of the coiling pin 1 is adjusted on the basis of the measured value of the outer diameter of the coil spring, as shown in FIG.
To drive the servo mechanism 22 for driving the screw mechanism, a drive unit 23 for driving the servo motor in response to a command from the control device 10, and the servo motor 22. Attached rotary encoder 24
Is provided, and a pulse signal corresponding to the rotation speed of the servo motor 22, that is, the moving amount of the coiling pin 1 is fed back to the control device 10 by the rotary encoder.

In the manufacturing process, in order to keep the free length and performance of the coil spring constant, as shown in FIG. 6, in the process of winding the pitch winding portion (effective winding portion) next to the winding start winding portion of the coil spring, When it is detected from the length of the wire rod sent out that the tip of the coiled coil spring is close to the position detected by the detector 11, the wire rod W is sent at a low speed and then detected by the detector 11. Control device 1
0 to drive motor 14 via drive unit 14
3 is actuated, the pitch tool 2 is moved, and the end winding is immediately started.

The position detected by the detector 11 is set to the predetermined free length of the coil spring minus the length of the end-end winding, and therefore the free length of the spring from the first end turn to the end of the pitch turn. Is always constant. The end winding is formed into a preset length, and when it is finished, the cylinder 1
The cutting tool 8 is operated by 9 and the wire is cut at the position of the cored bar 7 to complete one cycle.

Before and after cutting the wire rod, the amount of the wire rod fed in one sille, that is, the length of the wire rod used for the coil spring is the driving servo of the feed rollers 4, 5. -Ta 16
From the rotation angle of the rotary encoder 18
If the difference is within the allowable range, the coiled spring is selected by the selector 20. Is discharged to the non-defective product side, and to the defective product side if it is out of the allowable range.

At the sampling stage, immediately before the sampled coil spring reaches a predetermined length and is cut, for example, as shown in FIG. Then the outer diameter is measured and the tooling is corrected. The sampling rate varies depending on the outer diameter allowable range of the coil spring, but is one in 1500 to 2000 in one example. The sampling may be performed at the time when the winding end of the pitch portion is detected by the inspection device 11 or at the time when the end winding is finished. Further, in this system, it is possible to perform 100% inspection in some cases.

FIG. 7 is a flow chart showing stepwise outer diameter control starting from sampling. As shown in the figure, when the high speed feed of the pitch portion is completed, the parallel chuck 9 is actuated and its members 9a and 9b are used to coil the coil. Clap the spring. Since the coil spring is sandwiched by the planes of the members, the spring is held at a position on its diameter, and the distance between the members is equal to the diameter of the coil spring. Then, using a laser measuring instrument or the like, the member 9
The distance between a and 9b, that is, the outer diameter of the spring is measured, and the value is input to the computer of the control device 10 and compared with the reference value of the outer diameter. All of these operations are performed by the control device 10.

If the difference Δd is equal to 0 or almost 0 as a result of comparison between the outer diameter measurement value d and the reference value d0, the process directly returns to the manufacturing process. If the difference Δd is not equal to 0, that is, if it is a significant difference, after the end winding of the sampled spring is finished, the controller 10 operates the servomotor 22 via the drive unit 23, and Δd
After adjusting the position of the coiling pin 1 by a value corresponding to Δd so that becomes 0, the process returns to the manufacturing process.

The allowable range of the outer diameter of the coil spring is, for example, 10 ± 0.10 mm in the case of 10 mm. In this case, according to the method of the present invention, the difference Δd from the reference value d0 is 0.10 m by predicting the wear of the outer diameter and the coiling pin 1 and determining the sampling rate.
Since the outer diameter can be corrected before reaching m, and the position of the coiling pin 1 is adjusted so that Δd becomes 0, the outer diameter of the coil spring does not deviate from the allowable range.

[0021]

As described above, according to the present invention, the outer diameter of the coil spring is checked at a ratio of one to an appropriate number in the manufacturing process of the coil spring, and the touring is automatically corrected. The outer diameter of the manufactured coil spring can be maintained with high accuracy and can be kept within the allowable range at all times. In addition, sampled coil springs can also be used,
Since it is not necessary to make a close contact spring as in the conventional case, the wire diameter is not wasted, and the outer diameter can be quickly controlled.

[Brief description of drawings]

FIG. 1 is a schematic view schematically showing a main part of an example of an apparatus used for carrying out the method of the present invention.

FIG. 2 is a side view of an apparatus used for measuring the outer diameter of a coil spring.

FIG. 3 is a plan view of the device shown in FIG.

4 is a cross-sectional view taken along line AA of FIG.

FIG. 5 is an enlarged view of a main tool used for manufacturing a coil spring.

FIG. 6 is a flowchart showing an example of a manufacturing process of a coil spring related to the present invention.

FIG. 7 is a flowchart showing each step of the spring outer diameter control method according to the present invention.

FIG. 8 is a schematic side view of a conventional coil spring manufacturing apparatus.

[Explanation of symbols]

 1 Coiling Pin 8 Cutting Tool 9 Parallel Chuck 9a Parallel Chuck Member 9b Parallel Chuck Member 10 Controller

Claims (1)

[Claims] 1. In a manufacturing process of a coil spring in which a wire is brought into contact with a coiling pin to form a curved shape, the coil spring is sampled at an appropriate ratio of one, and the sampled coil spring has a predetermined length. Before reaching and cutting the coil spring, the outer diameter of the coil spring is measured by sandwiching the coil spring with a pair of members of a parallel chuck and measuring the distance between the members, and the measured value is input to a computer. Then, the position of the coiling pin is adjusted by a value corresponding to the difference between the measured value and the reference value by comparing with a predetermined reference value.